Notes sent by /note command now show the sender's account name to the receipient, instead of his character name.
New item ego types added: Robes 'of the Magi', (leather) frocks 'of Piety', 'Martial Arts' gowns and (leather) frocks.
The /ex command now displays the remaining amount of money your level 1 character may pick up before he receives 1 experience point, and therefore becomes ineligible for Ironman Deep Dive Challenge and Highlander Tournament. If a gold pile is greater than the remaining amount allowed, your character will only pick up a part of it that still fits in. Don't walk on it twice though!
Spears, hunting spears and tulwars can now correctly receive 'of perfection' ego power.
Some post-king titles have been modified.
Chaotic effects are now correctly resisted by monsters that should resist them.
The server settings (~d) now correctly inform about who may handle (true) artifacts and who doesn't.
/cou shortcut for /cough command has been disabled since it conflicted with another command.
Mimicry user are now able to pick a preferred immunity which will be gained from a form when polymorphing, accessible via 'm' menu.
The wilderness map now displays dungeon and tower entrances.
Characters do not stop running anymore after a short while, so they could in theory run across the whole world map if they aren't hindered by terrain or monsters.
Dungeon staircases are no longer generated right on the very edge of a sector, causing a crash.
Fixed eternal rain bug that would cause never-ending rain.
Small levels that would end half-way in the visible map area no longer use permanent wall tiles to fill up the remaining space, but instead show more stylish black background.
Players no longer attack at abnormal rate when 'running into' a monster.
Added missing feedback messages for certain mimic spells.
The inn is now called 'tavern' instead of 'home'.
Poison brand no longer also gives poison resistance (concerns 'venomous' weapons).
Targetting a friendly player via '(' key, as now mentioned in the guide, now works correctly. The player with the lowest hit points is targetted.
A bug in the luck bonus from artifact sets has been fixed, luck is now applied correctly.
Maia initiation failure and insanity deaths can no longer be caught by the instant-resurrection feature. They are instead permanent as they ought to be.
The Ironman Deep Dive Challenge dungeon never has exploration experience bonus, instead it now always gives 20% bonus exp as if it "hadn't been explored in ages".
Estimated ammo damage is now displayed correctly when inspecting ammo.
When inspecting slings, bows, crossbows and boomerangs, the estimate damage you'd do with them is now displayed too.
Runecraft auto-retaliation now works correctly.
Stat draining and getting disarming in Arena Monster Challenge is no longer possible.

4.4.9c is a mini-release. There is only a handful of server-side changes:
-added two special character slots to all player accounts
-toned down monsters in the pvp arena
-added monster "nether vortex" (nether realm only)
-magic mapping positioning in big_map mode has been fixed
-kinetic shield bug fixed

Some features have been released just now:
1) cure wounds targetted spell in holy curing, which is sort of a replacements for potions
2) fire/frost/lightning/acid bolt spells for istari
3) kobold race has been added
and some other stuff. Some aspects (macro wizard) of this stuff might not be completely implemented until next client release. The spells and Kobold race fully work though.

Server-side:
-Highlander dungeon always gives a 20% exp bonus, and in turn no exploration-bonus.
-Other players eligible for partying have their level show in light blue colour in @ screen.
-The player list (@) is now displayed properly in big_map mode.
-Ars Numenis has been buffed somewhat.
-A costume bug has been fixed (showing the wrong player as costumized) .
-Some skills unusable to certain characters are no longer displayed to them.
-It is now possible to specify an account name in some cases where character names had to be specified, most notably when adressing a private chat message.
-It is no longer possible to create a character of the same name as someone else's account name, or to create an account of the same name as someone else's character.
-Minions of Doom now use bolt spells instead of nether balls.
-Magic device skill has been adjusted for some classes. Mostly: Archers got a nerf and shamans and mindcrafters a buff.
-New spell 'Cure Wounds' has been added to 'Holy Curing' school: It is like quaffing a potion of cure light/serious/critical wounds. Use it together with '(' most wounded friendly
-The macro wizard provides 3 additional targetting methods: Self, most wounded friendly player nearby/cancel, most wounded friendly player nearby/self.
-The targetting method '(' aka most wounded friendly target now behaves in the following way:
-If in a party it ignores non-members.
-If all nearby friendly targets are fully healed, it prioritzes those with status impairments curable by 'Cure Wounds' spell (blind, cut, confusion, stun).
-Healing spells other than 'Cleansing Light' will no longer hurt Vampire players.
-Four elemental bolt spells (fire, frost, lightning, acid) have been added to magic schools 'Fire', 'Water', 'Air' and 'Earth'.
-A new race 'Kobold' has been added.
-Runecraft has been overhauled big time, once again. (A second patch to complete it is planned for the near future.)

-Ironman Deep Dive Challenge stuff:
-Characters in or slot-exclusive for IDDC are listed in grey colour in @ screen.
-IDDC score table shows batty status and class colour-
-If a party owner dies within the IDDC, ownership is transferred to another party member instead of disbanding the party.
-Titles 'Iron Champion' and 'Iron Emperor' are now available to those who make it through the IDDC (as non-winner or winner respectively).
-Slot-exclusive IDDC characters are automatically prevented from picking up too much gold, other players' items, and won't get 1 xp from eating a bad ration.

Further updates that were just applied:
-Character background text of Ents, Draconians, Maiar, Dark-elves and Vampires has been improved/added.
-Vampires of level 40+ consume the less food the higher their level, royalties consume the least amount possible (1 'food' per turn) no matter their level.
-Level 99 characters are now unaffected by experience draining effects
-Spell animation colours have been corrected.
-Ironman Deep Dive Challenge now prevents log-scumming (logging out and back in later to re-farm on the same depth): No exp/items/gold/credit is gained.
-Unique monsters may spawn inside the Ironman Deep Dive Challenge now even if they already exist elsewhere in the world at that moment.
-Mimic spells now state their mana cost if you don't have enough mana to cast them.
-Many mimic spells now require less mana and have a lower fail chance.
-The guide now mentions that INT has a positive effect on mimic spell fail chance.
-Death Fate dungeon is now a death fate.
-Halls of Mandos is now a 100-floor ironman dungeon (no tricks/towns/stuff, just plain ironman!).

Edit: If you have a "bugged" character regarding history text, ie one of the races listed above, you can just ask an admin to reroll your history.

..and a few more:
-Players may now target themselves with polymorph rods/wands.
-Bolt spells can now be targetted at a floor grid and will affect floor/items on it.
-Beams will always affect floor/items too now.
-Mimic spells have been further improved regarding mana cost, fail rate, damage, healing.

-IDDC-exclusive characters start out with the extra 300 gold right away, and in turn cannot pick up any gold from townies.
-Bolt spells will only damage the ground/loot if they don't hit a monster/player on that grid.
-Some monsters got a missing ANIMAL flag added as they should have.
-Ufthak of Cirith Ungol and Shagrath are now found in Cirith Ungol exclusively.

-Halls of Mandos is now a "classic" (basic) ironman dungeon, no towns or anything.
-Death Fate dungeon is now a death trap, because you cannot leave it.
-A potential polymorphing bug was fixed.
-Many mimic powers' mana cost and fail rate have been reduced.
-Mimic powers now have a minimum fail chance of 1% (no change) and a maximum fail chance of 99% (new).
-Spell animation colours and monster flicker colours have been made consistent and improved. As a result of this, a few monsters flicker in a somewhat different manner now, most notably Death Drake, Bronze/Gold Dragonrider, Sky Drake, Blade Angels.
-Level 99 characters are unaffected by exp-draining attacks.
-Ent, Maia, Dark-Elf, Vampire lore have been added/fixed/improved.
-Vampires consume less and less food with higher character level, starting at level 40. They consume minimal food if they attain winner status.
-Some error messages on failed login attempts have been improved.
-Ufthak and Shagrat are now restricted to Cirith Ungol dungeon to fit the lore.
-Precedence when writing private chat messages is now character name > account name > party name.
-Priest character creation STR/DEX recommendations were removed because they were usually unreachable.
-Rods/wands of polymorphing can now be targetted at oneself.
-Bolt spells can now be targetted at a specific grid, and will affect the floor/items on it if there is no hostile target there.
-All beam spells now affect floor/items too.
-Various animals got a missing ANIMAL flag added, so they are correctly treated as animals by the game (ESP, movement).
-Self-knowledge now correctly displays if a character doesn't require food.
-A bug introduced in 4.5.0 regarding spell/breath splash damage not correctly decreasing over radius has been fixed.
-Trap of Lose Memories has been enabled. It drains a bit experience, as well as INT and WIS and causes confusion.
-Runes (runecraft) can no longer be created on floor grids in towns.
-Mithril Ancile item now weighs 10.0 lbs instead of 12.0 lbs.
-The initial cost of spell Phase Door is now 2 mana instead of 1 mana.
-If there are multiple best (closest) targets, auto-targetting will now prefer awake ones over asleep ones.
-Increased the minimum/maximum amount of items dropped by The Shadow of Dol Guldur.
-HARD_STEAL and VHARD_STEAL store flags have been toned down a bit.
-Book stores now offer up to 6 pages of items instead of 4.
-Bolt/Arrow/Catapult trap kits are possibly dropped with enchantments and can correctly be enchanted now.
-Changing preferred immunity (mimicry-users) will also change the immunity you are currently gaining from your form accordinlgy, if possible. So there is no more need for re-polymorphing into the same form to make the chosen immunity apply.
-Fixed a glitch where !X feature would take the level of the item that needs to be identified to determine fail rate for activating rod/staff of identify, rather than the rod/staff's level.
-The Stone of Lore and the Mage Staff 'Eriril' can now be used with !X inscription for easy ID.
-The Iron Helm of Knowledge now hurts sanity again instead of hit points, but the damage has been toned down.
-Slow poison effects actually slow poison again, in the traditional way.
-Holy Curing spell 'Curing' has been split up into 'Curing' and 'Restoration'.
-Nature spell 'Recovery' has been tweaked a bit.
-Starter books a la 'Beginner Cantrips' have been added for priests and shamans.
-A slash command has been added to allow you to convert a character into a slot-exclusive (PvP or IDDC) character: /convertexclusive. This is not reversible, so use with care.

Ironman Deep Dive Challenge:
-Unique monsters can now spawn in IDDC even if they already exist elsewhere in the world.
-Players cannot log out, wait for the level to reset, then log in again to "farm" it. (Floor will turn 'stale'.)
-Monsters will no longer spawn 'live' on a level. That means once a level is cleared of all monsters, it is and stays perfectly safe (except if someone uses a summon monster scroll or some such..).
-Items of value below 15000 gold (internal, varies for actual player characters) that are enchanted _in town_ with _stolen_ enchantment scrolls, will receive a 100% off discount to prevent easy money cheezing.
-'slot-exclusive' IDDC characters now start with 300 extra gold right away, and are unable to gain any gold from townies instead.
-Quests attained while inside the IDDC require a lower number of monsters to be killed than usual.
-There is a flat 20% exp bonus in the IDDC now, which stacks with the usual Ironman exp bonus.
-There is now a slight, progressive +LUCK bonus in IDDC, starting after Menegroth (the first town at dungeon level 40).
-All weapon/armour offered by stores in dungeon towns is now 'good', which means the items are enchanted and have an increased chance to turn out having ego powers.
-A bug in item ownership on characters that withdraw from IDDC has been fixed.
-Players can no longer accidentally get recalled by other players or effects while in the IDDC. The only place where recall spells work on other players is now the final floor of the IDDC.
-If players missing Sauron enter a floor where Morgoth is, he will teleport out and summon Sauron in his stead.
-Characters that have already beaten Morgoth are actually able to enter floors with Morgoth on them (spawned by other players who still haven't killed him) in the IDDC.